The present invention relates to the scheduling of movement of plural units through a complex movement defining system, and in the embodiment disclosed, to the scheduling of the movement of freight trains over a railroad system, particularly the selective disabling of train location reports.
Systems and methods for scheduling the movement of trains over a rail network have been described in U.S. Pat. Nos. 6,154,735, 5,794,172, and 5,623,413, the disclosure of which is hereby incorporated by reference.
As disclosed in the referenced patents and applications, the complete disclosure of which is hereby incorporated herein by reference, railroads consist of three primary components (1) a rail infrastructure, including track, switches, a communications system and a control system; (2) rolling stock, including locomotives and cars; and, (3) personnel (or crew) that operate and maintain the railway. Generally, each of these components are employed by the use of a high level schedule which assigns people, locomotives, and cars to the various sections of track and allows them to move over that track in a manner that avoids collisions and permits the railway system to deliver goods to various destinations.
As disclosed in the referenced applications, a precision control system includes the use of an optimizing scheduler that will schedule all aspects of the rail system, taking into account the laws of physics, the policies of the railroad, the work rules of the personnel, the actual contractual terms of the contracts to the various customers and any boundary conditions or constraints which govern the possible solution or schedule such as passenger traffic, hours of operation of some of the facilities, track maintenance, work rules, etc. The combination of boundary conditions together with a figure of merit for each activity will result in a schedule which maximizes some figure of merit such as overall system cost.
As disclosed in the referenced applications, and upon determining a schedule, a movement plan may be created using the very fine grain structure necessary to actually control the movement of the train. Such fine grain structure may include assignment of personnel by name as well as the assignment of specific locomotives by number and may include the determination of the precise time or distance over time for the movement of the trains across the rail network and all the details of train handling, power levels, curves, grades, track topography, wind and weather conditions. This movement plan may be used to guide the manual dispatching of trains and controlling of track forces, or provided to the locomotives so that it can be implemented by the engineer or automatically by switchable actuation on the locomotive.
The planning system is hierarchical in nature in which the problem is abstracted to a relatively high level for the initial optimization process, and then the resulting course solution is mapped to a less abstract lower level for further optimization. Statistical processing is used at all levels to minimize the total computational load, making the overall process computationally feasible to implement. An expert system is used as a manager over these processes, and the expert system is also the tool by which various boundary conditions and constraints for the solution set are established. The use of an expert system in this capacity permits the user to supply the rules to be placed in the solution process.
Of significant value in planning train movement is the evaluating of the current location of the train, i.e., is the train on, ahead or behind schedule. Train location reports may be automatically issued by sensors along the line of road and are required to be submitted by train personnel at periodic intervals. The information in these reports as to the location of a train is used to automatically update the planned movement of the trains.
Currently, when a train stops to perform an activity such as a pickup, setout or crew change, some or part of the train (e.g., locomotive or selected cars) may be required to make movements along the track to accomplish the activity. This is true both in terminals and on the line of road. Such activity related moves typically do not advance the train along its route. Because the movement of the train may be automatically sensed and fed to the movement planner, significant disruption of the planning process may result. For example, the passage of a train by a switch in one direction may result in an automatic request for authority to use the adjacent section of track, with significant disruption of the planning function when the train is a short time later detected passing the same switch going in the opposite direction and automatically generates a request for authority to use an entirely different section of track.
One current solution is to prevent any impact on the movement planner by such train location information by the suspension of the use of the movement planner altogether in congested areas where long-haul, local industry or yard trains typically perform activities. This deprives the dispatcher of information as to the location of all trains in the area, including those trains which are not performing local movements, and represents a serious disadvantage in planning the movement of such trains.
An alternative current solution is the designation by the dispatcher of a specific train for manual operation when it approaches such an area. This deprives the dispatcher of the use of computerized planning tools and represents an unjustified allocation of the attention of the dispatcher.
It is accordingly an object of the present invention to permit the dispatcher to have continued access to the movement planner for those trains not engaged in local movements and to avoid manual intervention for such trains, thereby improving the profitability of the overall transportation system.
These and many other objects and advantages of the present invention will be readily apparent to one skilled in the art to which the invention pertains from a perusal of the claims, the appended drawings, and the following detailed description of the preferred embodiments.